Process for treatment of allergies

ABSTRACT

This invention relates to the immunotherapeutic treatment of allergies. More particularly, this invention relates to a process for treating allergies by administering to a mammal a pharmaceutically effective amount of gamma interferon.

TECHNICAL FIELD OF INVENTION

This invention relates to the immunotherapeutic treatment of allergies.More particularly, this invention relates to a process for suppressing amammal's allergic responses to allergens by means of increasing thebody's level of gamma interferon. According to this invention, naturalor recombinant gamma interferons are used to suppress the allergicresponses in a mammal.

BACKGROUND ART

The mechanisms involved in the induction and control of the allergicresponse are not completely understood. The allergic response is knownto be effected by antibody-mediated (immediate-type) hypersensitivity,cell-mediated (delayed-type) hypersensitivity, or both.

The antibody which is largely responsible for immediate typehypersensitivity reactions is immunoglobulin E ("IgE"). IgE antibodiesbind to the membranes of mast cells in skin or to basophils, specificmembrane receptors that recognize and bind the IgE molecule. The bindingaffinity of these classes of receptors for IgE is very high. A.Nisonoff, Molecular Immunology, p. 55 (1982).

After the IgE antibody is bound to the cell receptor on the mast cell orbasophil, an allergen binds to two or more IgE antibodies, causing themast cells or basophils to release numerous granules. These granulescontain the mediators of immediate hypersensitivity. These mediatorshave extremely potent contractile effects on the smaller airways of therespiratory tract. In mice and rats, serotonin is the principalmediator. In humans, histamine is the most important mediator ofimmediate hypersensitivity. SRS-A (Slow Reacting Substance ofAnaphylaxis) and ECF-A (Eosinophil Chemotactic Factor) are othermediators.

The symptoms of allergies include sinusitis, rhinitis, hives, headaches,post-nasal drip, coughing, sneezing, respiratory difficulties, sorethroats, allergic conjunctivitis, tightness in throat and chest, andloss of voice. In extreme cases the allergic response may cause fetalanaphylactic shock. The sneezing and respiratory difficulties arebrought on by contractions of smooth muscle of the respiratory tract.The other symptoms are brought on by the inflammation caused byincreased vascular permeability and the attraction of leukocytes.

Examples of antibody-mediated hypersensitivity are hay fever, asthma,food allergies and hives. This type of allergy is called atopy and it ischaracterized by sensitivity without prior exposure to the allergencausative agent. Delayed-type hypersensitivity is mediated by T-cells.Examples of cell-mediated hypersensitivity include allergic contactdermatitis, allergies to drugs, and a number of autoimmune diseases.

Typically, allergies are treated by a variety of drugs aimed atcounteracting the symptoms of an allergic reaction. However, these priortreatments are useful only on a short term basis, and often have adverseor disadvantageous and unwanted side effects. For example,antihistamines are often used to alleviate temporarily the generaldiscomfort caused by histamine release. Such drugs, however, causedrowsiness and therefore are not recommended for use during workinghours. Corticosteroids are also used to treat severe allergic reactions.However, these compounds immunosuppress the patient and thereby increasehis susceptibility to infectious disease. Inhaled salbutamol (known asalbuterol in the United Sates) is commonly used by asthma patients.However, like other sympathomimetic agents, salbutamol can have sidereactions such as hypertension, angina, vomiting, vertigo, and insomnia.

In view of the disadvantages of such prior allergy treatments,conventional means for treating allergies remain disappointing to thepatient, as well as to the clinician. Therefore, the need exists for aprocess which avoids these disadvantages and provides effectivetreatment for allergies.

DISCLOSURE OF THE INVENTION

The present invention solves the problems referred to above by providinga process for suppressing the allergic responses of a mammal bysupplementing the body's level of gamma interferon. Advantageously, theprocess of this invention enhances the body's natural immune response tothe allergen and, therefore, does not produce the variety of sideeffects which often accompany conventional allergy treatments.

BEST MODE OF CARRYING OUT THE INVENTION

In order that the invention herein described may be more fullyunderstood, the following detailed description is set forth.

In the description the following terms are employed:

IFN-γ (or gamma interferon)--Originally termed "immune interferon",IFN-γ is a lymphokine. IFN-γ is naturally produced in minute quantitiestogether with other lymphokines by stimulated lymphocytes. Its molecularweight has been determined to be 20,000-25,000 (or 17,000 withoutcarbohydrate). IFN-γ has also been cloned and expressed in varioushost-vector systems. The nucleotide sequence of cloned IFN-γ indicatesthat it is composed of 146 amino acids. As used in this application,"IFN-γ" includes all proteins, polypeptides, and peptides which arenatural or recombinant IFN-γs, or derivatives thereof, and which arecharacterized by the immunotherapeutic activity of these IFN-γs againstallergies. These include IFN-γ-like compounds from a variety of sourcessuch as natural IFN-γs, recombinant IFN-γs, and synthetic orsemi-synthetic IFN-γs.

Allergy--An abnormal or altered immunologic reaction induced by anallergen in an individual who suffers from hypersensitivity to thatallergen. The allergic reaction is an antibody-antigen reaction andincludes anaphylaxis, atopic diseases, serum sickens and contactdermatitis.

Allergen--The immunogen or antigen which induces the allergic response.

IgE--A glycoprotein with a molecular weight of about 130,000. Thisimmunoglobulin is responsible for immediate-type hypersensitivityreactions. When two IgE molecules are crosslinked with an allergen, mastcells and basophils release mediators such as histamines, SRS-A andECF-A.

This invention relates to a process for treating allergies. This processcomprises the steps of treating a mammal in a pharmaceuticallyacceptable manner with a pharmaceutically effective dose of gammainterferon ("IFN-γ").

Among the IFN-γs useful in the processes of this invention are theIFN-γs produced in vitro by a variety of cells in response to variousinterferon inducers. For example, these IFN-γs include IFN-γs producedin human buffy-coat leukocytes after exposure to PHA, Con A and SEA, M.DeLay et al. "Interferon Induced in Human Leukocytes By Mitogens:Production, Partial Purification and Characterization," Eur. J.Immunol., 10, pp. 877-83 (1980); in human splenocytes after stimulationwith SEA, R. Devos et al., "Isolation and Characterization of IGN-GammamRNA Derived From Mitogen-Induced Human Splenocytes," J. InterferonRes., 2, pp. 409-20 (1982); by an IL-2-independent murine T cell lineafter stimulation by phorbol 12-myristate 13-acetate, W. R. Benjamin etal., "Production of Immune Interferon by an Interleukin 2-IndependentMurine T cell line," Proc. Natl. Acad. Sci. USA, 79, pp. 5379-83 (1982);in lymphoid cells by using calcium ionophore A-23187, F. Dianzani etal., "Human Immune Interferon: Induction in Lymphoid Cells by a CalciumIonophore," Infection and Immunity, 29, pp. 561-63 (1980); and inthymocytes, G. H. Reem et al., "Gamma Interferon Induction in HumanThymocytes Activated by Lectins and B Cell Lines," Infection andImmunity, 37, pp. 216-21 (1982). See also, U.S. Pat. No. 4,376,821 andU.S. Pat. No. 4,376,822 and European patent application No. 63,482.

These natural IFN-γs have been subsequently purified to some extent andpartially characterized. See, for example, U.S. Pat. No. 4,289,690, U.S.Pat. No. 4,314,935 and U.S. Pat. No. 4,382,027, European patentapplication No. 87,686, O'Malley, "Affinity Chromatography of HumanImmune Interferon," Methods in Enzymology, 78 pp. 540-45 (1981), and Y.K. Yip et al., "Partial Purification and Characterization of Human γ(Immune) Interferon," Proc. Nat'l Acad. Sci. USA, 78, pp. 1601-05(1981).

IFN-γs useful in the processes of this invention may also be produced inlarge amounts using recombinant DNA technology. See, e.g., Europeanpatent application 88,540; R. Derynck et al., "Human Interferon γ IsEncoded By A Single Class Of mRNA," Nucleic Acids Research, 10, pp.3605-13, (1982); R. Derynck et al., "Expression Of The HumanInterferon-λ cDNA In Yeast," Nucleic Acids Res., 11, pp. 1819-37 (1983);R. Devos et al., "In Vitro Translation And Characterization Of HumanIFNγ mRNA," J. Clin. Hemator. Oncol., 11(4) p. 114 (1981); R. Devos etal., "Molecular Cloning of Human Immune Interferon cDNA And ItsExpression in Eukaryotic Cells," Nucleic Acids Research, 10 (8), pp.2487-501 (1982).

Without being bound by theory, we believe that the suppression of theallergic response in antibody mediated (immediate-type) hypersensitivityby the processes of our invention is due to the direct effect of IFN-γon the production of IgE through a general change in cellular immunity.Specifically, because hypersensitive individuals are immunodeficient ina way that deprives the body of its control mechanism for the productionof IgE, the administration according to this invention of IFN-γ, whichsubstance is normally produced by the cell-mediated immune system inhealthy individuals, supplies that missing control. As a result, theIFN-γ suppresses the production of IgE, so that the allergic reactiondoes not occur when the body is exposed to the offending allergen. Theoverall result of this treatment is to establish in hypersensitiveindividuals, the balance present in a normal individual's immuneresponse to antigens.

The process of this invention may be used to treat any mammal, includingcats, dogs, and humans. It is particularly useful for treatingallergies, including asthma, hay fever, food allergies, spontaneousanaphylaxis and other atopic diseases.

According to this invention, mammals are treated by the pharmaceuticallyacceptable administration of IFN-γ in a particularly effective dosageand for a period of time sufficient to suppress to some extent theallergic response.

More specifically, mammals are preferably treated with sub-cutaneous,intravenous or intramuscular injections of between 5 μg/M² and 500μg/M². Suppression of symptoms has been observed at doses as low as 5μg/M², although lower doses may also be effective. Furthermore, higherdoses also result in suppression of allergic symptoms. However, suchhigher doses are less preferred in treating allergies only because oftheir flu-like side effects. Such higher doses are, of course, usefulwhen the IFN-γ is also being used to treat other conditions, e.g., AIDSor cancer, in addition to allergies. This treatment is usually repeatedon a daily basis until a desired suppression of the allergic response isobserved. However, other dosage regimens are also useful. When thesymptoms have been alleviated to the desired level, treatment shouldcease. Patients may, however, require intermittent treatment on a longterm basis, as their physicians deem necessary or appropriate.

The IFN-γ can be administered in any pharmaceutically acceptable form.According to one embodiment of this invention, the formulation isisotonic and includes human serum albumin and salt buffers.

In order that the invention described herein may be more fullyunderstood, the following example is set forth. It should be understoodthat this example is for illustrative purposes only, and is not to beconstrued as limiting this invention in any manner.

EXAMPLE

In order to demonstrate the utility of the process of the presentinvention, we chose patients suffering from Acquired Immuno-DeficiencySyndrome ("AIDS"), whose severely compromised cellular immune systemprovides a good model for determination of the effect of IFN-γ onallergies.

Patients with AIDS have a depletion of the subset of T-cells involvednot only in delayed type hypersensitivity but also in the induction ofsuppressor cell activity, J. K. A. Nicholson et al., "ImmunoregulatorySubsets of the T Helper and T Suppressor Cell Populations in HomosexualMen With Chronic Unexplained Lymphadenopathy", J. Clin. Invest., vol.73, pp. 191-201 (1984), and may therefore have abnormal suppressorfunction. Patients with AIDS also characteristically have T4lymphocytedepletion and decreased production of lymphokines includinginterleukin-2 and IFN-γ. H. W. Murray et al., Impaired Production ofLymphokines and Immune (Gamma) Interferon in the AcquiredImmuno-deficiency Syndrome," N. Engl. J. Med., 310, pp. 883-89 (1984).Antibodies that mediate atopic disease, may be raised as part of thepolyclonal B-cell activation seen in AIDS patients. Additionally, AIDSpatients who have a history of atopic disease, appear to have arecrudescence of atopic symptoms which often coincides in time with theonset of AIDS.

An unusually high incidence of drug reactions has also been noted inAIDS patients, especially in treatment with high dose sulphonamides, H.S. Jafffe et al., "Complications of Co-trimoxazole in Therapy ofAIDS-associated Pneumocystis Carinii Pneumonia in Homosexual Men",Lancet, vol. III, pp. 1109-11 (1983). Also, an increased incidence ofatopic eczema has been noted in infants with AIDS. G. B. Scott et al.,"Acquired Immunodeficiency Syndrome in Infants," N. Eng. J. Med., vol.310, pp. 76-81 (1984); A. Rubinstein et al., "Acquired ImmunodeficiencySyndrome With Reversed T4/T8 Ratios in Infants Born to Promiscuous andDrug-addicted Mothers," JAMA, vol. 249, pp. 2350-56 (1983); P. A. Thomaset al., "Unexplained Immunodeficiency in children. A SurveillanceReport", JAMA, vol. 252, pp. 639-44 (1984). Accordingly, AIDS patientsare useful models for the use of IFN-γ as a treatment against allergies.

The following data demonstrate the effectiveness of IFN-γ, in this caserecombinant human IFN-γ, in the immunotherapeutic treatment ofallergies. The patients studied were suffering from AIDS and haddeveloped a recrudescence of atopic disease which coincided with, ordeveloped just before, the onset of AIDS.*

The two patients whose data are reported below, had a prior history ofatopic disease but in one, the atopic feature was new to the patient.After receiving recombinant human IFN-γ in a trial of immuno-restorationboth showed a striking improvement in atopic symptoms during therapy andrelapsed on its cessation.

The patients were treated at St. Mary's Hospital Medical School,Department of Immunology, Wright-Heming Institute, Paddington, London.Recombinant human IFN-γ was supplied by Biogen S. A., Geneva, forclinical testing. The specific activity of Biogen's recombinant humanIFN-γ was in the range of 10-20×10⁶ U/mg of protein.

Table 1 summarizes data for the two patients who were evaluated aftertreatment with IFN-γ:

                  TABLE 1                                                         ______________________________________                                        AT0PIC HISTORY IN SELECTED PATIENTS                                                                          Age of  Relation                                                              onset of                                                                              of Atopy                               Patient                                                                             Age/     Diag-   Atopic  atopic  to onset                               N°                                                                           sex      nosis   symptom symptoms                                                                              of AIDS                                ______________________________________                                        A2    49/F     PCP     hay fever*                                                                            16-20 yr  none                                                        asthma  45-49 yr  **                                                          milk*** 49    yr  +1 month                             A5    36/M     KS      asthma   5-18 yr  none                                                        asthma  36    yr  +3 months                                                   hay fever*                                                                             5-10 yr  none                                 ______________________________________                                         PCP = Pneumocystis carinii pneumonia                                          KS = Kaposi's Sarcoma                                                         * = Rhinitis, sneezing, conjunctivitis on exposure.                           ** = The incubation period of the HTLV 111 in this patient was thought to     be at least 5 years, therefore it is possible that the onset of asthma wa     related.                                                                      *** = Swelling on tongue and lips 5-10 minutes after every exposure to        undiluted milk.                                                          

As shown in Table 1, the patients had a history of atopic disease inchildhood or early adult life. In the cases studied, the onset of a newatopic symptom or the exacerbation of an old one occurred either duringthe period of persistent generalized lymphadenopathy (PGL) whichoccurred with the onset of AIDS, or around the time that the patientdeveloped overt symptoms of AIDS. In all the instances where atopyemerged during PGL, the lymphadenopathy was complicated by either fever,night sweats, weight loss, or oral candidiasis, which are thought to beprodomal symptoms for AIDS, and probably represent more subtle forms ofimmunodeficiency.

The two patients demonstrated substantial suppression of their allergicsymptoms while receiving recombinant human IFN-γ as part of a course oftherapeutic treatment aimed at immunorestoration. These patients weregiven IFN-γ as twice weekly intravenous infusions of 3,000 micrograms/M²(patient A2) and 10 micrograms/M² (patent A5). Patient A2 had a decreasein her marked sensitivity to milk and was able to tolerate undilutedmilk without significant allergic symptoms by the end of 8 weeks IFN-γtherapy. Her asthma had been quiescent before therapy and did not recurduring treatment and it was therefore not possible to monitor anyresponse.

Prior to IFN-γ treatment, patient A5 had suffered major asthmaticsymptoms necessitating the use of inhaled salbutamol at least oncedaily. There was no evidence of opportunistic lung infections. However,during the first 4 weeks of IFN-γ treatment his asthmatic symptomsgradually resolved; for the rest of the 8-week course and for 3 weeksfollowing, he remained asymptomatic and did not require bronchodilatortherapy. In the 4th week after cessation of IFN-γ treatment his asthmareturned, though not as severely; reintroduction of IFN-γ therapy againcaused resolution of the symptoms, this time within one week.

To analyze the effect of IFN-γ on the allergic response to otherallergies, prick tests were also performed on each patient using 16common allergens (Pharmacia) and a positive and negative control(histamine and diluent respectively). The tests were read at 10 minutesand were considered positive if a wheal of 2 mm or more was produced inthe presence of a negative response to the control. Delayed typehypersensitivity was tested using candida albicans, purified proteinderivative, and streptokinase/streptodornase injected intradermally. Apositive reaction was defined as induration and erythema at the sitewhen read at 48 hours. Serum IgE levels were also measured using a paperradio immuno-sorbant test (PRIST, Pharmacia). Finally, phenotypiclymphocyte subsets were determined by indirect fluorescent labellingwith monoclonal antibodies to the T4 and T8 antigens (OKT4, OKT8,GA-FITC, Coulter) and lymphokine production was measured in thesupernatants of mitogen stimulated lymphocytes.

The two patients showed increased Type 1 hypersensitivity as judged byfrequent positive cutaneous prick tests with common allergens. Boththese patients, however, demonstrated concomitant evidence ofimprovement in immune reactivity during IFN-γ therapy (Table II)manifested by conversion of previously negative delayed typehypersensitivity tests to positive.

                  TABLE II                                                        ______________________________________                                               Patient A2   Patient A5                                                       Pre     Post      Pre       Post                                              Treatment                                                                             Treatment Treatment Treatment                                         Allergic symptoms                                                             swelling                                                                              able to   asthma                                                      lips,   tolerate  required                                                    tongue, milk      daily     asymptom-                                         throat  without   salbutamol                                                                              atic, no                                          on drinking                                                                           severe    to control                                                                              broncho-                                          milk    symptoms  symptoms  dilator                                    ______________________________________                                        Kaposi's --        --        6 lesions                                                                             1 lesion                                 Sarcoma                                                                       DTH      0/3 +ve   1/3 +ve   0/3 +ve 1/3 +ve                                  T4 lymphs ×                                                                      0.26      0.48      0.48    0.77                                     10°/L                                                                  IFN-gamma production by lymphocytes                                           (mg protein)                                                                  unstimulated                                                                           0         516       0       845                                      + Con A  0         591       164     703                                      + PWM    0         463       261     279                                      + PHA    ND        ND        0       389                                      ______________________________________                                    

While we have hereinbefore presented a number of embodiments of thisinvention, it is apparent that our basic construction can be altered toprovide other embodiments which utilize the processes and compositionsof this invention. Therefore, it will be appreciated that the scope ofthis invention is to be defined by the claims appended hereto ratherthan by the specific embodiments which have been presented hereinbeforeby way of example.

We claim:
 1. A process for treating allergies comprising the step ofadministering to a mammal a pharmaceutically acceptable compositioncomprising a pharmaceutically effective amount of IFN-γ.
 2. The processaccording to claim 1, wherein the mammal is a human.
 3. The processaccording to claim 1, wherein the IFN-γ is selected from the groupconsisting of natural IFN-γ, recombinant IFN-γ, and derivatives thereofwhich are characterized by the immunotherapeutic activity of IFN-γagainst allergies.
 4. The process according to claim 3, wherein thecomposition is administered at a dosage of from about 5 μg/M² to about500 μg/M².
 5. The process according to claim 4, wherein the dosage is 10μg/M².
 6. The process according to claim 1, wherein the allergy isselected from the group consisting of asthma, spontaneous anaphylaxis,hay fever, and food allergies.